1. Field of the Invention
The present invention relates to a light-shielded photosensitive material roll which, in a lighted room, is loaded into a plate making machine using a photosensitive material.
2. Description of the Related Art
An elongated photosensitive material sheet is, in a state of being wound-up in a roll form on a winding core, loaded into a plate making machine which uses a photosensitive material. Usually, the side surfaces of the photosensitive material roll are covered by ring-shaped light-shielding sheets and the periphery of the photosensitive material roll is covered by a light-shielding leader so that the photosensitive material roll can be loaded into the plate making machine in a lighted room. (Hereinafter, a photosensitive material roll which is covered by light-shielding members is called a light-shielded photosensitive material roll.)
At the light-shielded photosensitive material roll, generally, the ring-shaped light-shielding sheets are fixed to the side surfaces of the photosensitive material roll so as to be nipped by the end surfaces of the winding core and the flanges of light-shielding flanged cylinders which are inserted into the opening portions of the winding core (see Japanese Patent Application Laid-Open (JP-A) No. 2000-181018).
Various types of photosensitive material roll driving shafts of plate making machines have been developed and put into use. Representative examples thereof are a rod-shaped driving shaft having the same outer diameter as the inner diameter of the winding core, and an outer-diameter-movable-type driving shaft in which the outer diameter of the distal end portion of the driving shaft is enlarged so as to be made equal to the inner diameter of the winding core after the driving shaft has been inserted into the winding core.
In a light-shielded photosensitive material roll in which the ring-shaped light-shielding sheets are fixed by light-shielding flanged cylinders, the cylindrical portions of the light-shielding flanged cylinders which are inserted into the winding core contact the driving shaft. Accordingly, in a conventional light-shielding flanged cylinder, the length of the tube portion must be made to be a length which is from the opening portion of the winding core to the enlarged portion of the outer-diameter-movable-type driving shaft.
Generally, in a light-shielding flanged cylinder which is used in a light-shielded photosensitive material roll, the outer diameter of the cylinder is substantially the same as the inner diameter of the winding core so that the cylinder securely contacts the inner wall of the winding core. Accordingly, if the length of the tube portion of the light-shielding flanged cylinder is excessively long, it is difficult to insert the light-shielding flanged cylinder into the winding core of the photosensitive material roll.
An object of the present invention is to overcome the above-described problems.
In order to achieve this object, in accordance with an aspect of the present invention, there is provided a photosensitive material roll which can be mounted in a predetermined machine via an adapter, comprising: a hollow, cylindrical winding core; an elongated photosensitive material sheet wound-up on the winding core; an annular member installed in an opening of the winding core; and a spacer mounted to an inner peripheral wall of the opening of the winding core on an imaginary extension, along a direction of installing the annular member, of an installing side distal end portion of the annular member, so as to be positioned at a position which is separated by a predetermined distance from the distal end portion, wherein the annular portion and the spacer can respectively work to integrally connect the winding core and the adapter.